Medical ultrasound is commonly used to facilitate needle injection procedures such as central venous line placement or various spinal anesthesia procedures. A commonly implemented technique involves locating anatomical landmarks (e.g. blood vessel or bone structures) using ultrasound and subsequently manually marking the patient's skin with a surgical marker in proximity to the ultrasound transducer. The ultrasound transducer is then removed, and the needle is inserted after positioning the needle at a location relative to the marking sites. The “marking approach” has been demonstrated to increase procedure success rates compared with the “blind approach” (i.e. inserting the needle without using medical imaging) when applied to spinal epidural anesthesia. (See, e.g., K. J. Chin, et al., “Ultrasound Imaging Facilitates Spinal Anesthesia in Adults with Difficult Surface Anatomic Landmarks.” Anesthesiology. 115(1), 2011, pp. 94-101. doi: 10.1097/ALN.0b013e31821a8ad4. PubMed PMID: WOS:000291925400015).
Current standard ultrasound devices do not offer a mechanism to facilitate accurate skin marking relative to the underlying anatomy while the ultrasound device is in place. Accordingly, improved devices and methods are needed.